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Linux/net/sunrpc/auth_gss/auth_gss.c

Version: ~ [ linux-5.4-rc7 ] ~ [ linux-5.3.10 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.83 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.153 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.200 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.200 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.76 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 /*
  2  * linux/net/sunrpc/auth_gss/auth_gss.c
  3  *
  4  * RPCSEC_GSS client authentication.
  5  *
  6  *  Copyright (c) 2000 The Regents of the University of Michigan.
  7  *  All rights reserved.
  8  *
  9  *  Dug Song       <dugsong@monkey.org>
 10  *  Andy Adamson   <andros@umich.edu>
 11  *
 12  *  Redistribution and use in source and binary forms, with or without
 13  *  modification, are permitted provided that the following conditions
 14  *  are met:
 15  *
 16  *  1. Redistributions of source code must retain the above copyright
 17  *     notice, this list of conditions and the following disclaimer.
 18  *  2. Redistributions in binary form must reproduce the above copyright
 19  *     notice, this list of conditions and the following disclaimer in the
 20  *     documentation and/or other materials provided with the distribution.
 21  *  3. Neither the name of the University nor the names of its
 22  *     contributors may be used to endorse or promote products derived
 23  *     from this software without specific prior written permission.
 24  *
 25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 36  */
 37 
 38 
 39 #include <linux/module.h>
 40 #include <linux/init.h>
 41 #include <linux/types.h>
 42 #include <linux/slab.h>
 43 #include <linux/sched.h>
 44 #include <linux/pagemap.h>
 45 #include <linux/sunrpc/clnt.h>
 46 #include <linux/sunrpc/auth.h>
 47 #include <linux/sunrpc/auth_gss.h>
 48 #include <linux/sunrpc/svcauth_gss.h>
 49 #include <linux/sunrpc/gss_err.h>
 50 #include <linux/workqueue.h>
 51 #include <linux/sunrpc/rpc_pipe_fs.h>
 52 #include <linux/sunrpc/gss_api.h>
 53 #include <asm/uaccess.h>
 54 
 55 static const struct rpc_authops authgss_ops;
 56 
 57 static const struct rpc_credops gss_credops;
 58 static const struct rpc_credops gss_nullops;
 59 
 60 #ifdef RPC_DEBUG
 61 # define RPCDBG_FACILITY        RPCDBG_AUTH
 62 #endif
 63 
 64 #define GSS_CRED_SLACK          1024
 65 /* length of a krb5 verifier (48), plus data added before arguments when
 66  * using integrity (two 4-byte integers): */
 67 #define GSS_VERF_SLACK          100
 68 
 69 struct gss_auth {
 70         struct kref kref;
 71         struct rpc_auth rpc_auth;
 72         struct gss_api_mech *mech;
 73         enum rpc_gss_svc service;
 74         struct rpc_clnt *client;
 75         /*
 76          * There are two upcall pipes; dentry[1], named "gssd", is used
 77          * for the new text-based upcall; dentry[0] is named after the
 78          * mechanism (for example, "krb5") and exists for
 79          * backwards-compatibility with older gssd's.
 80          */
 81         struct dentry *dentry[2];
 82 };
 83 
 84 /* pipe_version >= 0 if and only if someone has a pipe open. */
 85 static int pipe_version = -1;
 86 static atomic_t pipe_users = ATOMIC_INIT(0);
 87 static DEFINE_SPINLOCK(pipe_version_lock);
 88 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
 89 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
 90 
 91 static void gss_free_ctx(struct gss_cl_ctx *);
 92 static const struct rpc_pipe_ops gss_upcall_ops_v0;
 93 static const struct rpc_pipe_ops gss_upcall_ops_v1;
 94 
 95 static inline struct gss_cl_ctx *
 96 gss_get_ctx(struct gss_cl_ctx *ctx)
 97 {
 98         atomic_inc(&ctx->count);
 99         return ctx;
100 }
101 
102 static inline void
103 gss_put_ctx(struct gss_cl_ctx *ctx)
104 {
105         if (atomic_dec_and_test(&ctx->count))
106                 gss_free_ctx(ctx);
107 }
108 
109 /* gss_cred_set_ctx:
110  * called by gss_upcall_callback and gss_create_upcall in order
111  * to set the gss context. The actual exchange of an old context
112  * and a new one is protected by the inode->i_lock.
113  */
114 static void
115 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
116 {
117         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
118 
119         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
120                 return;
121         gss_get_ctx(ctx);
122         rcu_assign_pointer(gss_cred->gc_ctx, ctx);
123         set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
124         smp_mb__before_clear_bit();
125         clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
126 }
127 
128 static const void *
129 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
130 {
131         const void *q = (const void *)((const char *)p + len);
132         if (unlikely(q > end || q < p))
133                 return ERR_PTR(-EFAULT);
134         memcpy(res, p, len);
135         return q;
136 }
137 
138 static inline const void *
139 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
140 {
141         const void *q;
142         unsigned int len;
143 
144         p = simple_get_bytes(p, end, &len, sizeof(len));
145         if (IS_ERR(p))
146                 return p;
147         q = (const void *)((const char *)p + len);
148         if (unlikely(q > end || q < p))
149                 return ERR_PTR(-EFAULT);
150         dest->data = kmemdup(p, len, GFP_NOFS);
151         if (unlikely(dest->data == NULL))
152                 return ERR_PTR(-ENOMEM);
153         dest->len = len;
154         return q;
155 }
156 
157 static struct gss_cl_ctx *
158 gss_cred_get_ctx(struct rpc_cred *cred)
159 {
160         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
161         struct gss_cl_ctx *ctx = NULL;
162 
163         rcu_read_lock();
164         if (gss_cred->gc_ctx)
165                 ctx = gss_get_ctx(gss_cred->gc_ctx);
166         rcu_read_unlock();
167         return ctx;
168 }
169 
170 static struct gss_cl_ctx *
171 gss_alloc_context(void)
172 {
173         struct gss_cl_ctx *ctx;
174 
175         ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
176         if (ctx != NULL) {
177                 ctx->gc_proc = RPC_GSS_PROC_DATA;
178                 ctx->gc_seq = 1;        /* NetApp 6.4R1 doesn't accept seq. no. 0 */
179                 spin_lock_init(&ctx->gc_seq_lock);
180                 atomic_set(&ctx->count,1);
181         }
182         return ctx;
183 }
184 
185 #define GSSD_MIN_TIMEOUT (60 * 60)
186 static const void *
187 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
188 {
189         const void *q;
190         unsigned int seclen;
191         unsigned int timeout;
192         u32 window_size;
193         int ret;
194 
195         /* First unsigned int gives the lifetime (in seconds) of the cred */
196         p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
197         if (IS_ERR(p))
198                 goto err;
199         if (timeout == 0)
200                 timeout = GSSD_MIN_TIMEOUT;
201         ctx->gc_expiry = jiffies + (unsigned long)timeout * HZ * 3 / 4;
202         /* Sequence number window. Determines the maximum number of simultaneous requests */
203         p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
204         if (IS_ERR(p))
205                 goto err;
206         ctx->gc_win = window_size;
207         /* gssd signals an error by passing ctx->gc_win = 0: */
208         if (ctx->gc_win == 0) {
209                 /* in which case, p points to  an error code which we ignore */
210                 p = ERR_PTR(-EACCES);
211                 goto err;
212         }
213         /* copy the opaque wire context */
214         p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
215         if (IS_ERR(p))
216                 goto err;
217         /* import the opaque security context */
218         p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
219         if (IS_ERR(p))
220                 goto err;
221         q = (const void *)((const char *)p + seclen);
222         if (unlikely(q > end || q < p)) {
223                 p = ERR_PTR(-EFAULT);
224                 goto err;
225         }
226         ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
227         if (ret < 0) {
228                 p = ERR_PTR(ret);
229                 goto err;
230         }
231         return q;
232 err:
233         dprintk("RPC:       gss_fill_context returning %ld\n", -PTR_ERR(p));
234         return p;
235 }
236 
237 #define UPCALL_BUF_LEN 128
238 
239 struct gss_upcall_msg {
240         atomic_t count;
241         uid_t   uid;
242         struct rpc_pipe_msg msg;
243         struct list_head list;
244         struct gss_auth *auth;
245         struct rpc_inode *inode;
246         struct rpc_wait_queue rpc_waitqueue;
247         wait_queue_head_t waitqueue;
248         struct gss_cl_ctx *ctx;
249         char databuf[UPCALL_BUF_LEN];
250 };
251 
252 static int get_pipe_version(void)
253 {
254         int ret;
255 
256         spin_lock(&pipe_version_lock);
257         if (pipe_version >= 0) {
258                 atomic_inc(&pipe_users);
259                 ret = pipe_version;
260         } else
261                 ret = -EAGAIN;
262         spin_unlock(&pipe_version_lock);
263         return ret;
264 }
265 
266 static void put_pipe_version(void)
267 {
268         if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
269                 pipe_version = -1;
270                 spin_unlock(&pipe_version_lock);
271         }
272 }
273 
274 static void
275 gss_release_msg(struct gss_upcall_msg *gss_msg)
276 {
277         if (!atomic_dec_and_test(&gss_msg->count))
278                 return;
279         put_pipe_version();
280         BUG_ON(!list_empty(&gss_msg->list));
281         if (gss_msg->ctx != NULL)
282                 gss_put_ctx(gss_msg->ctx);
283         rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
284         kfree(gss_msg);
285 }
286 
287 static struct gss_upcall_msg *
288 __gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
289 {
290         struct gss_upcall_msg *pos;
291         list_for_each_entry(pos, &rpci->in_downcall, list) {
292                 if (pos->uid != uid)
293                         continue;
294                 atomic_inc(&pos->count);
295                 dprintk("RPC:       gss_find_upcall found msg %p\n", pos);
296                 return pos;
297         }
298         dprintk("RPC:       gss_find_upcall found nothing\n");
299         return NULL;
300 }
301 
302 /* Try to add an upcall to the pipefs queue.
303  * If an upcall owned by our uid already exists, then we return a reference
304  * to that upcall instead of adding the new upcall.
305  */
306 static inline struct gss_upcall_msg *
307 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
308 {
309         struct rpc_inode *rpci = gss_msg->inode;
310         struct inode *inode = &rpci->vfs_inode;
311         struct gss_upcall_msg *old;
312 
313         spin_lock(&inode->i_lock);
314         old = __gss_find_upcall(rpci, gss_msg->uid);
315         if (old == NULL) {
316                 atomic_inc(&gss_msg->count);
317                 list_add(&gss_msg->list, &rpci->in_downcall);
318         } else
319                 gss_msg = old;
320         spin_unlock(&inode->i_lock);
321         return gss_msg;
322 }
323 
324 static void
325 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
326 {
327         list_del_init(&gss_msg->list);
328         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
329         wake_up_all(&gss_msg->waitqueue);
330         atomic_dec(&gss_msg->count);
331 }
332 
333 static void
334 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
335 {
336         struct inode *inode = &gss_msg->inode->vfs_inode;
337 
338         if (list_empty(&gss_msg->list))
339                 return;
340         spin_lock(&inode->i_lock);
341         if (!list_empty(&gss_msg->list))
342                 __gss_unhash_msg(gss_msg);
343         spin_unlock(&inode->i_lock);
344 }
345 
346 static void
347 gss_upcall_callback(struct rpc_task *task)
348 {
349         struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
350                         struct gss_cred, gc_base);
351         struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
352         struct inode *inode = &gss_msg->inode->vfs_inode;
353 
354         spin_lock(&inode->i_lock);
355         if (gss_msg->ctx)
356                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
357         else
358                 task->tk_status = gss_msg->msg.errno;
359         gss_cred->gc_upcall = NULL;
360         rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
361         spin_unlock(&inode->i_lock);
362         gss_release_msg(gss_msg);
363 }
364 
365 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
366 {
367         gss_msg->msg.data = &gss_msg->uid;
368         gss_msg->msg.len = sizeof(gss_msg->uid);
369 }
370 
371 static void gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
372                                 struct rpc_clnt *clnt, int machine_cred)
373 {
374         char *p = gss_msg->databuf;
375         int len = 0;
376 
377         gss_msg->msg.len = sprintf(gss_msg->databuf, "mech=%s uid=%d ",
378                                    gss_msg->auth->mech->gm_name,
379                                    gss_msg->uid);
380         p += gss_msg->msg.len;
381         if (clnt->cl_principal) {
382                 len = sprintf(p, "target=%s ", clnt->cl_principal);
383                 p += len;
384                 gss_msg->msg.len += len;
385         }
386         if (machine_cred) {
387                 len = sprintf(p, "service=* ");
388                 p += len;
389                 gss_msg->msg.len += len;
390         } else if (!strcmp(clnt->cl_program->name, "nfs4_cb")) {
391                 len = sprintf(p, "service=nfs ");
392                 p += len;
393                 gss_msg->msg.len += len;
394         }
395         len = sprintf(p, "\n");
396         gss_msg->msg.len += len;
397 
398         gss_msg->msg.data = gss_msg->databuf;
399         BUG_ON(gss_msg->msg.len > UPCALL_BUF_LEN);
400 }
401 
402 static void gss_encode_msg(struct gss_upcall_msg *gss_msg,
403                                 struct rpc_clnt *clnt, int machine_cred)
404 {
405         if (pipe_version == 0)
406                 gss_encode_v0_msg(gss_msg);
407         else /* pipe_version == 1 */
408                 gss_encode_v1_msg(gss_msg, clnt, machine_cred);
409 }
410 
411 static inline struct gss_upcall_msg *
412 gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid, struct rpc_clnt *clnt,
413                 int machine_cred)
414 {
415         struct gss_upcall_msg *gss_msg;
416         int vers;
417 
418         gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
419         if (gss_msg == NULL)
420                 return ERR_PTR(-ENOMEM);
421         vers = get_pipe_version();
422         if (vers < 0) {
423                 kfree(gss_msg);
424                 return ERR_PTR(vers);
425         }
426         gss_msg->inode = RPC_I(gss_auth->dentry[vers]->d_inode);
427         INIT_LIST_HEAD(&gss_msg->list);
428         rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
429         init_waitqueue_head(&gss_msg->waitqueue);
430         atomic_set(&gss_msg->count, 1);
431         gss_msg->uid = uid;
432         gss_msg->auth = gss_auth;
433         gss_encode_msg(gss_msg, clnt, machine_cred);
434         return gss_msg;
435 }
436 
437 static struct gss_upcall_msg *
438 gss_setup_upcall(struct rpc_clnt *clnt, struct gss_auth *gss_auth, struct rpc_cred *cred)
439 {
440         struct gss_cred *gss_cred = container_of(cred,
441                         struct gss_cred, gc_base);
442         struct gss_upcall_msg *gss_new, *gss_msg;
443         uid_t uid = cred->cr_uid;
444 
445         gss_new = gss_alloc_msg(gss_auth, uid, clnt, gss_cred->gc_machine_cred);
446         if (IS_ERR(gss_new))
447                 return gss_new;
448         gss_msg = gss_add_msg(gss_auth, gss_new);
449         if (gss_msg == gss_new) {
450                 struct inode *inode = &gss_new->inode->vfs_inode;
451                 int res = rpc_queue_upcall(inode, &gss_new->msg);
452                 if (res) {
453                         gss_unhash_msg(gss_new);
454                         gss_msg = ERR_PTR(res);
455                 }
456         } else
457                 gss_release_msg(gss_new);
458         return gss_msg;
459 }
460 
461 static void warn_gssd(void)
462 {
463         static unsigned long ratelimit;
464         unsigned long now = jiffies;
465 
466         if (time_after(now, ratelimit)) {
467                 printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
468                                 "Please check user daemon is running.\n");
469                 ratelimit = now + 15*HZ;
470         }
471 }
472 
473 static inline int
474 gss_refresh_upcall(struct rpc_task *task)
475 {
476         struct rpc_cred *cred = task->tk_msg.rpc_cred;
477         struct gss_auth *gss_auth = container_of(cred->cr_auth,
478                         struct gss_auth, rpc_auth);
479         struct gss_cred *gss_cred = container_of(cred,
480                         struct gss_cred, gc_base);
481         struct gss_upcall_msg *gss_msg;
482         struct inode *inode;
483         int err = 0;
484 
485         dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
486                                                                 cred->cr_uid);
487         gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
488         if (PTR_ERR(gss_msg) == -EAGAIN) {
489                 /* XXX: warning on the first, under the assumption we
490                  * shouldn't normally hit this case on a refresh. */
491                 warn_gssd();
492                 task->tk_timeout = 15*HZ;
493                 rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
494                 return 0;
495         }
496         if (IS_ERR(gss_msg)) {
497                 err = PTR_ERR(gss_msg);
498                 goto out;
499         }
500         inode = &gss_msg->inode->vfs_inode;
501         spin_lock(&inode->i_lock);
502         if (gss_cred->gc_upcall != NULL)
503                 rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
504         else if (gss_msg->ctx != NULL) {
505                 gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_msg->ctx);
506                 gss_cred->gc_upcall = NULL;
507                 rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
508         } else if (gss_msg->msg.errno >= 0) {
509                 task->tk_timeout = 0;
510                 gss_cred->gc_upcall = gss_msg;
511                 /* gss_upcall_callback will release the reference to gss_upcall_msg */
512                 atomic_inc(&gss_msg->count);
513                 rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
514         } else
515                 err = gss_msg->msg.errno;
516         spin_unlock(&inode->i_lock);
517         gss_release_msg(gss_msg);
518 out:
519         dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
520                         task->tk_pid, cred->cr_uid, err);
521         return err;
522 }
523 
524 static inline int
525 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
526 {
527         struct inode *inode;
528         struct rpc_cred *cred = &gss_cred->gc_base;
529         struct gss_upcall_msg *gss_msg;
530         DEFINE_WAIT(wait);
531         int err = 0;
532 
533         dprintk("RPC:       gss_upcall for uid %u\n", cred->cr_uid);
534 retry:
535         gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
536         if (PTR_ERR(gss_msg) == -EAGAIN) {
537                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
538                                 pipe_version >= 0, 15*HZ);
539                 if (err)
540                         goto out;
541                 if (pipe_version < 0)
542                         warn_gssd();
543                 goto retry;
544         }
545         if (IS_ERR(gss_msg)) {
546                 err = PTR_ERR(gss_msg);
547                 goto out;
548         }
549         inode = &gss_msg->inode->vfs_inode;
550         for (;;) {
551                 prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
552                 spin_lock(&inode->i_lock);
553                 if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
554                         break;
555                 }
556                 spin_unlock(&inode->i_lock);
557                 if (fatal_signal_pending(current)) {
558                         err = -ERESTARTSYS;
559                         goto out_intr;
560                 }
561                 schedule();
562         }
563         if (gss_msg->ctx)
564                 gss_cred_set_ctx(cred, gss_msg->ctx);
565         else
566                 err = gss_msg->msg.errno;
567         spin_unlock(&inode->i_lock);
568 out_intr:
569         finish_wait(&gss_msg->waitqueue, &wait);
570         gss_release_msg(gss_msg);
571 out:
572         dprintk("RPC:       gss_create_upcall for uid %u result %d\n",
573                         cred->cr_uid, err);
574         return err;
575 }
576 
577 static ssize_t
578 gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
579                 char __user *dst, size_t buflen)
580 {
581         char *data = (char *)msg->data + msg->copied;
582         size_t mlen = min(msg->len, buflen);
583         unsigned long left;
584 
585         left = copy_to_user(dst, data, mlen);
586         if (left == mlen) {
587                 msg->errno = -EFAULT;
588                 return -EFAULT;
589         }
590 
591         mlen -= left;
592         msg->copied += mlen;
593         msg->errno = 0;
594         return mlen;
595 }
596 
597 #define MSG_BUF_MAXSIZE 1024
598 
599 static ssize_t
600 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
601 {
602         const void *p, *end;
603         void *buf;
604         struct gss_upcall_msg *gss_msg;
605         struct inode *inode = filp->f_path.dentry->d_inode;
606         struct gss_cl_ctx *ctx;
607         uid_t uid;
608         ssize_t err = -EFBIG;
609 
610         if (mlen > MSG_BUF_MAXSIZE)
611                 goto out;
612         err = -ENOMEM;
613         buf = kmalloc(mlen, GFP_NOFS);
614         if (!buf)
615                 goto out;
616 
617         err = -EFAULT;
618         if (copy_from_user(buf, src, mlen))
619                 goto err;
620 
621         end = (const void *)((char *)buf + mlen);
622         p = simple_get_bytes(buf, end, &uid, sizeof(uid));
623         if (IS_ERR(p)) {
624                 err = PTR_ERR(p);
625                 goto err;
626         }
627 
628         err = -ENOMEM;
629         ctx = gss_alloc_context();
630         if (ctx == NULL)
631                 goto err;
632 
633         err = -ENOENT;
634         /* Find a matching upcall */
635         spin_lock(&inode->i_lock);
636         gss_msg = __gss_find_upcall(RPC_I(inode), uid);
637         if (gss_msg == NULL) {
638                 spin_unlock(&inode->i_lock);
639                 goto err_put_ctx;
640         }
641         list_del_init(&gss_msg->list);
642         spin_unlock(&inode->i_lock);
643 
644         p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
645         if (IS_ERR(p)) {
646                 err = PTR_ERR(p);
647                 switch (err) {
648                 case -EACCES:
649                         gss_msg->msg.errno = err;
650                         err = mlen;
651                         break;
652                 case -EFAULT:
653                 case -ENOMEM:
654                 case -EINVAL:
655                 case -ENOSYS:
656                         gss_msg->msg.errno = -EAGAIN;
657                         break;
658                 default:
659                         printk(KERN_CRIT "%s: bad return from "
660                                 "gss_fill_context: %ld\n", __func__, err);
661                         BUG();
662                 }
663                 goto err_release_msg;
664         }
665         gss_msg->ctx = gss_get_ctx(ctx);
666         err = mlen;
667 
668 err_release_msg:
669         spin_lock(&inode->i_lock);
670         __gss_unhash_msg(gss_msg);
671         spin_unlock(&inode->i_lock);
672         gss_release_msg(gss_msg);
673 err_put_ctx:
674         gss_put_ctx(ctx);
675 err:
676         kfree(buf);
677 out:
678         dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
679         return err;
680 }
681 
682 static int gss_pipe_open(struct inode *inode, int new_version)
683 {
684         int ret = 0;
685 
686         spin_lock(&pipe_version_lock);
687         if (pipe_version < 0) {
688                 /* First open of any gss pipe determines the version: */
689                 pipe_version = new_version;
690                 rpc_wake_up(&pipe_version_rpc_waitqueue);
691                 wake_up(&pipe_version_waitqueue);
692         } else if (pipe_version != new_version) {
693                 /* Trying to open a pipe of a different version */
694                 ret = -EBUSY;
695                 goto out;
696         }
697         atomic_inc(&pipe_users);
698 out:
699         spin_unlock(&pipe_version_lock);
700         return ret;
701 
702 }
703 
704 static int gss_pipe_open_v0(struct inode *inode)
705 {
706         return gss_pipe_open(inode, 0);
707 }
708 
709 static int gss_pipe_open_v1(struct inode *inode)
710 {
711         return gss_pipe_open(inode, 1);
712 }
713 
714 static void
715 gss_pipe_release(struct inode *inode)
716 {
717         struct rpc_inode *rpci = RPC_I(inode);
718         struct gss_upcall_msg *gss_msg;
719 
720 restart:
721         spin_lock(&inode->i_lock);
722         list_for_each_entry(gss_msg, &rpci->in_downcall, list) {
723 
724                 if (!list_empty(&gss_msg->msg.list))
725                         continue;
726                 gss_msg->msg.errno = -EPIPE;
727                 atomic_inc(&gss_msg->count);
728                 __gss_unhash_msg(gss_msg);
729                 spin_unlock(&inode->i_lock);
730                 gss_release_msg(gss_msg);
731                 goto restart;
732         }
733         spin_unlock(&inode->i_lock);
734 
735         put_pipe_version();
736 }
737 
738 static void
739 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
740 {
741         struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
742 
743         if (msg->errno < 0) {
744                 dprintk("RPC:       gss_pipe_destroy_msg releasing msg %p\n",
745                                 gss_msg);
746                 atomic_inc(&gss_msg->count);
747                 gss_unhash_msg(gss_msg);
748                 if (msg->errno == -ETIMEDOUT)
749                         warn_gssd();
750                 gss_release_msg(gss_msg);
751         }
752 }
753 
754 /*
755  * NOTE: we have the opportunity to use different
756  * parameters based on the input flavor (which must be a pseudoflavor)
757  */
758 static struct rpc_auth *
759 gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
760 {
761         struct gss_auth *gss_auth;
762         struct rpc_auth * auth;
763         int err = -ENOMEM; /* XXX? */
764 
765         dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
766 
767         if (!try_module_get(THIS_MODULE))
768                 return ERR_PTR(err);
769         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
770                 goto out_dec;
771         gss_auth->client = clnt;
772         err = -EINVAL;
773         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
774         if (!gss_auth->mech) {
775                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!\n",
776                                 __func__, flavor);
777                 goto err_free;
778         }
779         gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
780         if (gss_auth->service == 0)
781                 goto err_put_mech;
782         auth = &gss_auth->rpc_auth;
783         auth->au_cslack = GSS_CRED_SLACK >> 2;
784         auth->au_rslack = GSS_VERF_SLACK >> 2;
785         auth->au_ops = &authgss_ops;
786         auth->au_flavor = flavor;
787         atomic_set(&auth->au_count, 1);
788         kref_init(&gss_auth->kref);
789 
790         /*
791          * Note: if we created the old pipe first, then someone who
792          * examined the directory at the right moment might conclude
793          * that we supported only the old pipe.  So we instead create
794          * the new pipe first.
795          */
796         gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
797                                          "gssd",
798                                          clnt, &gss_upcall_ops_v1,
799                                          RPC_PIPE_WAIT_FOR_OPEN);
800         if (IS_ERR(gss_auth->dentry[1])) {
801                 err = PTR_ERR(gss_auth->dentry[1]);
802                 goto err_put_mech;
803         }
804 
805         gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
806                                          gss_auth->mech->gm_name,
807                                          clnt, &gss_upcall_ops_v0,
808                                          RPC_PIPE_WAIT_FOR_OPEN);
809         if (IS_ERR(gss_auth->dentry[0])) {
810                 err = PTR_ERR(gss_auth->dentry[0]);
811                 goto err_unlink_pipe_1;
812         }
813         err = rpcauth_init_credcache(auth);
814         if (err)
815                 goto err_unlink_pipe_0;
816 
817         return auth;
818 err_unlink_pipe_0:
819         rpc_unlink(gss_auth->dentry[0]);
820 err_unlink_pipe_1:
821         rpc_unlink(gss_auth->dentry[1]);
822 err_put_mech:
823         gss_mech_put(gss_auth->mech);
824 err_free:
825         kfree(gss_auth);
826 out_dec:
827         module_put(THIS_MODULE);
828         return ERR_PTR(err);
829 }
830 
831 static void
832 gss_free(struct gss_auth *gss_auth)
833 {
834         rpc_unlink(gss_auth->dentry[1]);
835         rpc_unlink(gss_auth->dentry[0]);
836         gss_mech_put(gss_auth->mech);
837 
838         kfree(gss_auth);
839         module_put(THIS_MODULE);
840 }
841 
842 static void
843 gss_free_callback(struct kref *kref)
844 {
845         struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
846 
847         gss_free(gss_auth);
848 }
849 
850 static void
851 gss_destroy(struct rpc_auth *auth)
852 {
853         struct gss_auth *gss_auth;
854 
855         dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
856                         auth, auth->au_flavor);
857 
858         rpcauth_destroy_credcache(auth);
859 
860         gss_auth = container_of(auth, struct gss_auth, rpc_auth);
861         kref_put(&gss_auth->kref, gss_free_callback);
862 }
863 
864 /*
865  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
866  * to the server with the GSS control procedure field set to
867  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
868  * all RPCSEC_GSS state associated with that context.
869  */
870 static int
871 gss_destroying_context(struct rpc_cred *cred)
872 {
873         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
874         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
875         struct rpc_task *task;
876 
877         if (gss_cred->gc_ctx == NULL ||
878             test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
879                 return 0;
880 
881         gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
882         cred->cr_ops = &gss_nullops;
883 
884         /* Take a reference to ensure the cred will be destroyed either
885          * by the RPC call or by the put_rpccred() below */
886         get_rpccred(cred);
887 
888         task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
889         if (!IS_ERR(task))
890                 rpc_put_task(task);
891 
892         put_rpccred(cred);
893         return 1;
894 }
895 
896 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
897  * to create a new cred or context, so they check that things have been
898  * allocated before freeing them. */
899 static void
900 gss_do_free_ctx(struct gss_cl_ctx *ctx)
901 {
902         dprintk("RPC:       gss_free_ctx\n");
903 
904         kfree(ctx->gc_wire_ctx.data);
905         kfree(ctx);
906 }
907 
908 static void
909 gss_free_ctx_callback(struct rcu_head *head)
910 {
911         struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
912         gss_do_free_ctx(ctx);
913 }
914 
915 static void
916 gss_free_ctx(struct gss_cl_ctx *ctx)
917 {
918         struct gss_ctx *gc_gss_ctx;
919 
920         gc_gss_ctx = rcu_dereference(ctx->gc_gss_ctx);
921         rcu_assign_pointer(ctx->gc_gss_ctx, NULL);
922         call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
923         if (gc_gss_ctx)
924                 gss_delete_sec_context(&gc_gss_ctx);
925 }
926 
927 static void
928 gss_free_cred(struct gss_cred *gss_cred)
929 {
930         dprintk("RPC:       gss_free_cred %p\n", gss_cred);
931         kfree(gss_cred);
932 }
933 
934 static void
935 gss_free_cred_callback(struct rcu_head *head)
936 {
937         struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
938         gss_free_cred(gss_cred);
939 }
940 
941 static void
942 gss_destroy_nullcred(struct rpc_cred *cred)
943 {
944         struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
945         struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
946         struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
947 
948         rcu_assign_pointer(gss_cred->gc_ctx, NULL);
949         call_rcu(&cred->cr_rcu, gss_free_cred_callback);
950         if (ctx)
951                 gss_put_ctx(ctx);
952         kref_put(&gss_auth->kref, gss_free_callback);
953 }
954 
955 static void
956 gss_destroy_cred(struct rpc_cred *cred)
957 {
958 
959         if (gss_destroying_context(cred))
960                 return;
961         gss_destroy_nullcred(cred);
962 }
963 
964 /*
965  * Lookup RPCSEC_GSS cred for the current process
966  */
967 static struct rpc_cred *
968 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
969 {
970         return rpcauth_lookup_credcache(auth, acred, flags);
971 }
972 
973 static struct rpc_cred *
974 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
975 {
976         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
977         struct gss_cred *cred = NULL;
978         int err = -ENOMEM;
979 
980         dprintk("RPC:       gss_create_cred for uid %d, flavor %d\n",
981                 acred->uid, auth->au_flavor);
982 
983         if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
984                 goto out_err;
985 
986         rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
987         /*
988          * Note: in order to force a call to call_refresh(), we deliberately
989          * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
990          */
991         cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
992         cred->gc_service = gss_auth->service;
993         cred->gc_machine_cred = acred->machine_cred;
994         kref_get(&gss_auth->kref);
995         return &cred->gc_base;
996 
997 out_err:
998         dprintk("RPC:       gss_create_cred failed with error %d\n", err);
999         return ERR_PTR(err);
1000 }
1001 
1002 static int
1003 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1004 {
1005         struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1006         struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1007         int err;
1008 
1009         do {
1010                 err = gss_create_upcall(gss_auth, gss_cred);
1011         } while (err == -EAGAIN);
1012         return err;
1013 }
1014 
1015 static int
1016 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1017 {
1018         struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1019 
1020         if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1021                 goto out;
1022         /* Don't match with creds that have expired. */
1023         if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1024                 return 0;
1025         if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1026                 return 0;
1027 out:
1028         if (acred->machine_cred != gss_cred->gc_machine_cred)
1029                 return 0;
1030         return (rc->cr_uid == acred->uid);
1031 }
1032 
1033 /*
1034 * Marshal credentials.
1035 * Maybe we should keep a cached credential for performance reasons.
1036 */
1037 static __be32 *
1038 gss_marshal(struct rpc_task *task, __be32 *p)
1039 {
1040         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1041         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1042                                                  gc_base);
1043         struct gss_cl_ctx       *ctx = gss_cred_get_ctx(cred);
1044         __be32          *cred_len;
1045         struct rpc_rqst *req = task->tk_rqstp;
1046         u32             maj_stat = 0;
1047         struct xdr_netobj mic;
1048         struct kvec     iov;
1049         struct xdr_buf  verf_buf;
1050 
1051         dprintk("RPC: %5u gss_marshal\n", task->tk_pid);
1052 
1053         *p++ = htonl(RPC_AUTH_GSS);
1054         cred_len = p++;
1055 
1056         spin_lock(&ctx->gc_seq_lock);
1057         req->rq_seqno = ctx->gc_seq++;
1058         spin_unlock(&ctx->gc_seq_lock);
1059 
1060         *p++ = htonl((u32) RPC_GSS_VERSION);
1061         *p++ = htonl((u32) ctx->gc_proc);
1062         *p++ = htonl((u32) req->rq_seqno);
1063         *p++ = htonl((u32) gss_cred->gc_service);
1064         p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1065         *cred_len = htonl((p - (cred_len + 1)) << 2);
1066 
1067         /* We compute the checksum for the verifier over the xdr-encoded bytes
1068          * starting with the xid and ending at the end of the credential: */
1069         iov.iov_base = xprt_skip_transport_header(task->tk_xprt,
1070                                         req->rq_snd_buf.head[0].iov_base);
1071         iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1072         xdr_buf_from_iov(&iov, &verf_buf);
1073 
1074         /* set verifier flavor*/
1075         *p++ = htonl(RPC_AUTH_GSS);
1076 
1077         mic.data = (u8 *)(p + 1);
1078         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1079         if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1080                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1081         } else if (maj_stat != 0) {
1082                 printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1083                 goto out_put_ctx;
1084         }
1085         p = xdr_encode_opaque(p, NULL, mic.len);
1086         gss_put_ctx(ctx);
1087         return p;
1088 out_put_ctx:
1089         gss_put_ctx(ctx);
1090         return NULL;
1091 }
1092 
1093 static int gss_renew_cred(struct rpc_task *task)
1094 {
1095         struct rpc_cred *oldcred = task->tk_msg.rpc_cred;
1096         struct gss_cred *gss_cred = container_of(oldcred,
1097                                                  struct gss_cred,
1098                                                  gc_base);
1099         struct rpc_auth *auth = oldcred->cr_auth;
1100         struct auth_cred acred = {
1101                 .uid = oldcred->cr_uid,
1102                 .machine_cred = gss_cred->gc_machine_cred,
1103         };
1104         struct rpc_cred *new;
1105 
1106         new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1107         if (IS_ERR(new))
1108                 return PTR_ERR(new);
1109         task->tk_msg.rpc_cred = new;
1110         put_rpccred(oldcred);
1111         return 0;
1112 }
1113 
1114 /*
1115 * Refresh credentials. XXX - finish
1116 */
1117 static int
1118 gss_refresh(struct rpc_task *task)
1119 {
1120         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1121         int ret = 0;
1122 
1123         if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1124                         !test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1125                 ret = gss_renew_cred(task);
1126                 if (ret < 0)
1127                         goto out;
1128                 cred = task->tk_msg.rpc_cred;
1129         }
1130 
1131         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1132                 ret = gss_refresh_upcall(task);
1133 out:
1134         return ret;
1135 }
1136 
1137 /* Dummy refresh routine: used only when destroying the context */
1138 static int
1139 gss_refresh_null(struct rpc_task *task)
1140 {
1141         return -EACCES;
1142 }
1143 
1144 static __be32 *
1145 gss_validate(struct rpc_task *task, __be32 *p)
1146 {
1147         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1148         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1149         __be32          seq;
1150         struct kvec     iov;
1151         struct xdr_buf  verf_buf;
1152         struct xdr_netobj mic;
1153         u32             flav,len;
1154         u32             maj_stat;
1155 
1156         dprintk("RPC: %5u gss_validate\n", task->tk_pid);
1157 
1158         flav = ntohl(*p++);
1159         if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1160                 goto out_bad;
1161         if (flav != RPC_AUTH_GSS)
1162                 goto out_bad;
1163         seq = htonl(task->tk_rqstp->rq_seqno);
1164         iov.iov_base = &seq;
1165         iov.iov_len = sizeof(seq);
1166         xdr_buf_from_iov(&iov, &verf_buf);
1167         mic.data = (u8 *)p;
1168         mic.len = len;
1169 
1170         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1171         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1172                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1173         if (maj_stat) {
1174                 dprintk("RPC: %5u gss_validate: gss_verify_mic returned "
1175                                 "error 0x%08x\n", task->tk_pid, maj_stat);
1176                 goto out_bad;
1177         }
1178         /* We leave it to unwrap to calculate au_rslack. For now we just
1179          * calculate the length of the verifier: */
1180         cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1181         gss_put_ctx(ctx);
1182         dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
1183                         task->tk_pid);
1184         return p + XDR_QUADLEN(len);
1185 out_bad:
1186         gss_put_ctx(ctx);
1187         dprintk("RPC: %5u gss_validate failed.\n", task->tk_pid);
1188         return NULL;
1189 }
1190 
1191 static inline int
1192 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1193                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1194 {
1195         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1196         struct xdr_buf  integ_buf;
1197         __be32          *integ_len = NULL;
1198         struct xdr_netobj mic;
1199         u32             offset;
1200         __be32          *q;
1201         struct kvec     *iov;
1202         u32             maj_stat = 0;
1203         int             status = -EIO;
1204 
1205         integ_len = p++;
1206         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1207         *p++ = htonl(rqstp->rq_seqno);
1208 
1209         status = encode(rqstp, p, obj);
1210         if (status)
1211                 return status;
1212 
1213         if (xdr_buf_subsegment(snd_buf, &integ_buf,
1214                                 offset, snd_buf->len - offset))
1215                 return status;
1216         *integ_len = htonl(integ_buf.len);
1217 
1218         /* guess whether we're in the head or the tail: */
1219         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1220                 iov = snd_buf->tail;
1221         else
1222                 iov = snd_buf->head;
1223         p = iov->iov_base + iov->iov_len;
1224         mic.data = (u8 *)(p + 1);
1225 
1226         maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1227         status = -EIO; /* XXX? */
1228         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1229                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1230         else if (maj_stat)
1231                 return status;
1232         q = xdr_encode_opaque(p, NULL, mic.len);
1233 
1234         offset = (u8 *)q - (u8 *)p;
1235         iov->iov_len += offset;
1236         snd_buf->len += offset;
1237         return 0;
1238 }
1239 
1240 static void
1241 priv_release_snd_buf(struct rpc_rqst *rqstp)
1242 {
1243         int i;
1244 
1245         for (i=0; i < rqstp->rq_enc_pages_num; i++)
1246                 __free_page(rqstp->rq_enc_pages[i]);
1247         kfree(rqstp->rq_enc_pages);
1248 }
1249 
1250 static int
1251 alloc_enc_pages(struct rpc_rqst *rqstp)
1252 {
1253         struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1254         int first, last, i;
1255 
1256         if (snd_buf->page_len == 0) {
1257                 rqstp->rq_enc_pages_num = 0;
1258                 return 0;
1259         }
1260 
1261         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1262         last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1263         rqstp->rq_enc_pages_num = last - first + 1 + 1;
1264         rqstp->rq_enc_pages
1265                 = kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1266                                 GFP_NOFS);
1267         if (!rqstp->rq_enc_pages)
1268                 goto out;
1269         for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1270                 rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1271                 if (rqstp->rq_enc_pages[i] == NULL)
1272                         goto out_free;
1273         }
1274         rqstp->rq_release_snd_buf = priv_release_snd_buf;
1275         return 0;
1276 out_free:
1277         rqstp->rq_enc_pages_num = i;
1278         priv_release_snd_buf(rqstp);
1279 out:
1280         return -EAGAIN;
1281 }
1282 
1283 static inline int
1284 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1285                 kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
1286 {
1287         struct xdr_buf  *snd_buf = &rqstp->rq_snd_buf;
1288         u32             offset;
1289         u32             maj_stat;
1290         int             status;
1291         __be32          *opaque_len;
1292         struct page     **inpages;
1293         int             first;
1294         int             pad;
1295         struct kvec     *iov;
1296         char            *tmp;
1297 
1298         opaque_len = p++;
1299         offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1300         *p++ = htonl(rqstp->rq_seqno);
1301 
1302         status = encode(rqstp, p, obj);
1303         if (status)
1304                 return status;
1305 
1306         status = alloc_enc_pages(rqstp);
1307         if (status)
1308                 return status;
1309         first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1310         inpages = snd_buf->pages + first;
1311         snd_buf->pages = rqstp->rq_enc_pages;
1312         snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1313         /* Give the tail its own page, in case we need extra space in the
1314          * head when wrapping: */
1315         if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1316                 tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1317                 memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1318                 snd_buf->tail[0].iov_base = tmp;
1319         }
1320         maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1321         /* RPC_SLACK_SPACE should prevent this ever happening: */
1322         BUG_ON(snd_buf->len > snd_buf->buflen);
1323         status = -EIO;
1324         /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1325          * done anyway, so it's safe to put the request on the wire: */
1326         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1327                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1328         else if (maj_stat)
1329                 return status;
1330 
1331         *opaque_len = htonl(snd_buf->len - offset);
1332         /* guess whether we're in the head or the tail: */
1333         if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1334                 iov = snd_buf->tail;
1335         else
1336                 iov = snd_buf->head;
1337         p = iov->iov_base + iov->iov_len;
1338         pad = 3 - ((snd_buf->len - offset - 1) & 3);
1339         memset(p, 0, pad);
1340         iov->iov_len += pad;
1341         snd_buf->len += pad;
1342 
1343         return 0;
1344 }
1345 
1346 static int
1347 gss_wrap_req(struct rpc_task *task,
1348              kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
1349 {
1350         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1351         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1352                         gc_base);
1353         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1354         int             status = -EIO;
1355 
1356         dprintk("RPC: %5u gss_wrap_req\n", task->tk_pid);
1357         if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1358                 /* The spec seems a little ambiguous here, but I think that not
1359                  * wrapping context destruction requests makes the most sense.
1360                  */
1361                 status = encode(rqstp, p, obj);
1362                 goto out;
1363         }
1364         switch (gss_cred->gc_service) {
1365                 case RPC_GSS_SVC_NONE:
1366                         status = encode(rqstp, p, obj);
1367                         break;
1368                 case RPC_GSS_SVC_INTEGRITY:
1369                         status = gss_wrap_req_integ(cred, ctx, encode,
1370                                                                 rqstp, p, obj);
1371                         break;
1372                 case RPC_GSS_SVC_PRIVACY:
1373                         status = gss_wrap_req_priv(cred, ctx, encode,
1374                                         rqstp, p, obj);
1375                         break;
1376         }
1377 out:
1378         gss_put_ctx(ctx);
1379         dprintk("RPC: %5u gss_wrap_req returning %d\n", task->tk_pid, status);
1380         return status;
1381 }
1382 
1383 static inline int
1384 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1385                 struct rpc_rqst *rqstp, __be32 **p)
1386 {
1387         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1388         struct xdr_buf integ_buf;
1389         struct xdr_netobj mic;
1390         u32 data_offset, mic_offset;
1391         u32 integ_len;
1392         u32 maj_stat;
1393         int status = -EIO;
1394 
1395         integ_len = ntohl(*(*p)++);
1396         if (integ_len & 3)
1397                 return status;
1398         data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1399         mic_offset = integ_len + data_offset;
1400         if (mic_offset > rcv_buf->len)
1401                 return status;
1402         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1403                 return status;
1404 
1405         if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1406                                 mic_offset - data_offset))
1407                 return status;
1408 
1409         if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1410                 return status;
1411 
1412         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1413         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1414                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1415         if (maj_stat != GSS_S_COMPLETE)
1416                 return status;
1417         return 0;
1418 }
1419 
1420 static inline int
1421 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1422                 struct rpc_rqst *rqstp, __be32 **p)
1423 {
1424         struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1425         u32 offset;
1426         u32 opaque_len;
1427         u32 maj_stat;
1428         int status = -EIO;
1429 
1430         opaque_len = ntohl(*(*p)++);
1431         offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1432         if (offset + opaque_len > rcv_buf->len)
1433                 return status;
1434         /* remove padding: */
1435         rcv_buf->len = offset + opaque_len;
1436 
1437         maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1438         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1439                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1440         if (maj_stat != GSS_S_COMPLETE)
1441                 return status;
1442         if (ntohl(*(*p)++) != rqstp->rq_seqno)
1443                 return status;
1444 
1445         return 0;
1446 }
1447 
1448 
1449 static int
1450 gss_unwrap_resp(struct rpc_task *task,
1451                 kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
1452 {
1453         struct rpc_cred *cred = task->tk_msg.rpc_cred;
1454         struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1455                         gc_base);
1456         struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1457         __be32          *savedp = p;
1458         struct kvec     *head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1459         int             savedlen = head->iov_len;
1460         int             status = -EIO;
1461 
1462         if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1463                 goto out_decode;
1464         switch (gss_cred->gc_service) {
1465                 case RPC_GSS_SVC_NONE:
1466                         break;
1467                 case RPC_GSS_SVC_INTEGRITY:
1468                         status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1469                         if (status)
1470                                 goto out;
1471                         break;
1472                 case RPC_GSS_SVC_PRIVACY:
1473                         status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1474                         if (status)
1475                                 goto out;
1476                         break;
1477         }
1478         /* take into account extra slack for integrity and privacy cases: */
1479         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1480                                                 + (savedlen - head->iov_len);
1481 out_decode:
1482         status = decode(rqstp, p, obj);
1483 out:
1484         gss_put_ctx(ctx);
1485         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
1486                         status);
1487         return status;
1488 }
1489 
1490 static const struct rpc_authops authgss_ops = {
1491         .owner          = THIS_MODULE,
1492         .au_flavor      = RPC_AUTH_GSS,
1493         .au_name        = "RPCSEC_GSS",
1494         .create         = gss_create,
1495         .destroy        = gss_destroy,
1496         .lookup_cred    = gss_lookup_cred,
1497         .crcreate       = gss_create_cred
1498 };
1499 
1500 static const struct rpc_credops gss_credops = {
1501         .cr_name        = "AUTH_GSS",
1502         .crdestroy      = gss_destroy_cred,
1503         .cr_init        = gss_cred_init,
1504         .crbind         = rpcauth_generic_bind_cred,
1505         .crmatch        = gss_match,
1506         .crmarshal      = gss_marshal,
1507         .crrefresh      = gss_refresh,
1508         .crvalidate     = gss_validate,
1509         .crwrap_req     = gss_wrap_req,
1510         .crunwrap_resp  = gss_unwrap_resp,
1511 };
1512 
1513 static const struct rpc_credops gss_nullops = {
1514         .cr_name        = "AUTH_GSS",
1515         .crdestroy      = gss_destroy_nullcred,
1516         .crbind         = rpcauth_generic_bind_cred,
1517         .crmatch        = gss_match,
1518         .crmarshal      = gss_marshal,
1519         .crrefresh      = gss_refresh_null,
1520         .crvalidate     = gss_validate,
1521         .crwrap_req     = gss_wrap_req,
1522         .crunwrap_resp  = gss_unwrap_resp,
1523 };
1524 
1525 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1526         .upcall         = gss_pipe_upcall,
1527         .downcall       = gss_pipe_downcall,
1528         .destroy_msg    = gss_pipe_destroy_msg,
1529         .open_pipe      = gss_pipe_open_v0,
1530         .release_pipe   = gss_pipe_release,
1531 };
1532 
1533 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1534         .upcall         = gss_pipe_upcall,
1535         .downcall       = gss_pipe_downcall,
1536         .destroy_msg    = gss_pipe_destroy_msg,
1537         .open_pipe      = gss_pipe_open_v1,
1538         .release_pipe   = gss_pipe_release,
1539 };
1540 
1541 /*
1542  * Initialize RPCSEC_GSS module
1543  */
1544 static int __init init_rpcsec_gss(void)
1545 {
1546         int err = 0;
1547 
1548         err = rpcauth_register(&authgss_ops);
1549         if (err)
1550                 goto out;
1551         err = gss_svc_init();
1552         if (err)
1553                 goto out_unregister;
1554         rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1555         return 0;
1556 out_unregister:
1557         rpcauth_unregister(&authgss_ops);
1558 out:
1559         return err;
1560 }
1561 
1562 static void __exit exit_rpcsec_gss(void)
1563 {
1564         gss_svc_shutdown();
1565         rpcauth_unregister(&authgss_ops);
1566         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1567 }
1568 
1569 MODULE_LICENSE("GPL");
1570 module_init(init_rpcsec_gss)
1571 module_exit(exit_rpcsec_gss)
1572 

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